In regions that are susceptible to high winds, such as hurricane force winds, there is a strong desire and need to protect buildings from impacts resulting from wind-borne debris. For example, the state of Florida has set standards that buildings situated in High Velocity Hurricane Zones (e.g., Miami-Dade and Broward Counties) must be provided with protection against wind-borne debris caused by hurricanes. In particular, Miami-Dade County has implemented strict test protocols for wind-borne debris that require walls and building panels to withstand certain impacts, such as large or small-missile impacts. A product is declared large-missile resistant if it can withstand various impacts with a piece of lumber weighing approximately 9 pounds, measuring two-by-four in size (“2×4”), and traveling at a speed of 50 feet per second (34 mph). Products that are able to meet the Miami-Dade County test protocols are issued a Miami-Dade County Notice of Acceptance (NOA).
Various types of sheet materials have been used in the construction of buildings as a barrier fabric to block water and air while allowing transmission of moisture vapor from the building interior. These so-called housewrap products are typically applied over the sheathing layer of the building and beneath the exterior surface layer of brick or siding. Generally, housewrap products are flexible, inexpensive, and relatively easy to install. However, they typically offer little to no impact resistance and are susceptible to being punctured or torn. As a result, these products are unable to meet the Miami-Dade County requirements for impact resistance.
To meet the Miami-Dade County impact-resistant requirements, various products have been developed, such as steel or cementitious wall panels. For example, Miami-Dade County NOA No. 02-1216.01 describes an approved impact resistant wall panel comprising rib roll-formed galvanized steel that is made by Reynolds Metal Co. This product is generally expensive to produce and install, as well as being relatively heavy and cumbersome. Other commercially available products have been developed that are directed to composite structures that include one or more cementitious layers, a foam core, and a reinforcing mesh. For example, U.S. Pat. No. 6,119,422 describes a multilayered impact resistant building panel having an insulating foam core that is sandwiched between a fiberglass mesh reinforced cementitious panel and a plywood sheet, and an impact resistant heavy and thick nylon mesh adhered between the cementitious panel and the foam core. These wall panels are also expensive to produce and difficult to install.
Thus, there still exists a need for a product that can meet the Miami-Dade County impact-resistant requirements while being relatively inexpensive and easy to install.